I started with the technique mentioned above, but the colour wasn't what I wanted so I went a slightly different way about it. Selected the parts I wanted to paint. Copy/paste, use "Hue/Saturation" to get the colour, then messed around with some of the contrasts.
Just a tip. Try other settings in the pull down menu and you'll get different effect that may suit the lighting or shading of the car and area. Good job though! The second version was really nice
And if the point of all this was to see if the wheels would look good on a red Miata, I personally think they are too big... especially for the front of the car. It make it look like it has negative rake, even if it doesn't.